[Rob Brownfield]

It is fishing related in that its my fishing wagon that needs fixing!! 

I need to replace my brake discs (rotors) and thus need to remove my calipers. 14mm bolts (T2) removed, caliper safely off and out the way leaving the U shapes pad holders (Part 9 in the diagram) in place and bolted to the main wheel hub assembly. (Thus still restricting the removal of the rotors).

Two 17mm (T3 on the diagram) bolts are required to be removed. One wont move, the other sheared off! Would I be right in saying that the main hub assembly where the bolt goes through wont be threaded, only the pad holder (9), meaning  that if I shear the other bolt, I can remove the pad holder with sheared bolts in situ and get access to the sheared bolts that way to remove them.

[Mike Barrio]

16 fuel ups ...... and no brakes?

[Mike Barrio]

Sorry, no idea Rob

Cheers
Mike

[Rob Brownfield]

16 fuel ups ...... and no brakes?

100,000 miles of hard use and first bit of work I have had to do on it...not my Volvo...this is for my Subaru Outback

[Ben Dixon]

Where did the bolt shear?  Have you only got the head to look at?  If it is not threaded close to the bolt head then the assembly will not be threaded, you should be able to see from where it is broken whether it is threaded or not.  Heat the other one before you try to move it and twat it a couple of time with a hammer then try to tighten before undoing.

Cheers

Ben

[Rob Brownfield]

Indeed it is not threaded which suggested it was not a threaded part...just wanted reassurance before taking an angle gringer to the other one. 

Can't apply heat due to the proximity to anti lock sensor and wiring and rubber hose.

As the rotor is loose anyway I can just pull both the rotor and pad assembly at the same time and then remove the studded parts of the bolt or, if they are well goosed, replace the holder.

[Ben Dixon]

In that case, WD40 then twat the bolt head via a bit of brass and try to tighten it before trying to remove it.  If that fails, call Kev, he'll come around with a big hammer and smash it off for you.

Ben

[Sandy Nelson]

If it is not threaded close to the bolt head then the assembly will not be threaded,

Maybe, but it could be, i wouldn't use that as a guide, sorry Ben
However i would not expect the Hub to be threaded, as screwing a bolt into two threaded housings would not be normal engineering practice. Thats not to say it isn't so, but i would doubt it. These housings often have a small degree of adjustment too so it is unlikely

A good soak in a release agent (wd40 if you don't a have proper one), will help, but i would suspect you have already done that.
If the cables are too close for  heat gun/blowtorch then i'm surprised you can get an angled grinder in there

I'd go for shearing off the other head and then hit the support from the inside with a tapometer, I'd guess the plain portion is corroded to the hub due to salt/water and general shit over 100,000 miles, I hate cars

Sandy

[Kevin Muir]

Ben said

twat it a couple of time with a hammer

Guys, you have no idea how happy this makes me feel

At long last ben has seen the benefits of hitting things with hammers, happy days.

Seriously Rob, without checking the brake pad carrier off the car it would be difficult to confirm but most of them are not threaded, it is the section of the hub that is threaded.  I usually split the pad carrier from the hub with the two bolts and leave the caliper and pad carrier as one unit if changing discs.  Remember you will have to backoff the caliper piston a good bit for the new thicker disc and new pads.

As said above, give the other bolt a good spray with a suitable release oil , give it a decent smack with a hammer to give it a fright then try to tighten it just a little with a long 1/2" bar or a 600mm long bar with a piece of pipe on the end (pack it with tape if you are worried about it slipping) with an appropriate socket, 6 point out of preference.

Then try to slacken the bolt, if it will not undo it will shear, either way you should be able to get the pad holder off the car allowing you to remove the discs.

If the discs will not come off due to rust between the inside of the disc and the hub assembly, the easiest way of sorting this is to smash off the thin section of disc that the pads press against with a decent sized hammer (I love big hammers) cut it off with a grinder if you feel squeamish hitting it with a hammer. You may have to split the section of the disk that covers the hub, using your grinder cut a deep slot into the top edge of this casting at 90 degrees to the face cutting in towards the hub (behind the disc) but try not to cut into the hub.  Then with a good but blunt cold chisel try to split the cast iton with a few good blows of a decent hammer, .  If you have not cut into the casting far enough, spin the disc through 180 degrees and repear, it should just fall off .  remember two or three good hard blows rather than 20 from a toffee hammer.  We all feel the need to hit our cars with a hammer from time to time at least this is justified, try to savour the moment, I know I did

Clean up the hub and remember to spread copper slip on the inside of your new discs so that they come off easier than the ones on the car just now after another 100K.

Grind off and excess broken bolt on the hub and CAREFULLY centre dab the centre of the broken bolt, drill with a series of drills to remove some material from the centre of the bolt and you should be able to pick out the section of broken bolt or get an "easy out" to remove it, remember a good quality one.

Good luck, let us know how you get on.

Remember hammers are your friend

Kev.

[Hamish Young]

Kevs toolkit:




H

[Ben Dixon]

Best post I've read in a while

Confused though Kev, you capitalised "carefully"  

[Noel Kelly]

Lol lol lol longest post from Kev EVER! 

Rob if you need good easy out's I can loan you some. If you're going that route don't drill 2 large a hole through the bolt for now.

Kev I worked on 747's for years you would have loved it. First thing you need when working on those beasts is a bigger hammer

[Kevin Muir]

Firstly Mr Young, the photo of that hammer is just no use at all.

It's made from wood but about the right size if made from metal.  little hammers are only for tapping pins in or breaking up toffee.  For this job we need a proper hammer 4lb minimum and hit the chisel don't tickle it with the hammer.

Carefully centre dap the broken bolt, I really do mean CAREFULLY or it all goes south very quickly when you drill out all the threads in the hub and need to fit a helicoil or a new hub, not a good start to a day.

It may sound rough but the discs are only cast iron and do split very easily given the right persuasion, eg grinder and hammer, in that order.

Cheeky blighters

Kev.

[Peter McCallum]

Cheeky blighters

 Their only telling the truth

[Iain Goolager]

Rob,
Cars are rubbish and fixing them is for people who will always have a desire for hardship.

I'd wager a years salary that only item 9 is threaded, don't know anything about Subarus but threading both sections would be very silly and very uncommon.

Silly question, did you shear the bolt? If so, how much torque did it take? What tools were you using? ring spanner? Socket with ratchet or extension bar? Assume a scale of
- not a lot , the bugger just snapped.
- quite a bit, my face was quite red
- a lot, I felt my spine crack and let out a little bit of gas.
 
Ideally these type of fixings break out very easily with a touch of heat but as you feel that is not a possibility I would look at using the best fitting socket and torque bar tp see if I could move the second bolt while fully prared to shear that one too. If it moves, great, of it shears great.
If it does shear them you should have 2 studs with enough meat to get hold of with a set of vase grips or a 4" pipe wrench if you have one. Note: this will require that bit of heat that I mentioned prior to screwing out bolts.

If you don't have vice grips you can place one stud in a vice, heat around the bolt then tap the pad retainer (item 9) so as to unscrew it from the stationary bolt.

If you do not have access to burning gear then you CAN bore out the studs but you will have to be careful. 

Cut the remaining exposed section of studs from item 9 (unless you want to use them to hold the piece steady in a vise for the time being). I would not attempt to use easy outs for a couple of reasons. The pilot hole would have to be quite large and central. If the easy out snaps you are farped, and as that sucker is solid in there then I'd not risk it.  I would be looking to totally drill out the stud to a ba hair shy of the crest of the female thread on item 9. If you have a good and sharp series of drill bits and a tap set to clean and tidy the hole then you will be laughing - if that initial pilot hole was dead centre.

The hardest part of giving advise is the fact that I cannot see the job and like most other guys would chop and change strategies as they felt their way through the options.

Good luck.

Iain.